In recent years, the technology for recycling a used lip-type seal has been developed as part of the environmental antipollution measures. As shown in FIG. 1, a conventional lip-type seal formed in consideration of recycling is known (see Japanese Published Unexamined Patent Publication No. 2002-364759, for example). This conventional lip-type seal is made up of a metallic core ring 1, a first rubber-made sealing member 2 that contains the core ring 1 and that is shaped almost conical, a second resinous sealing member 3 that adjoins the first sealing member 2 and that is shaped almost conical, and a metallic backup ring 4 that adjoins the second sealing member 3.
In this lip-type seal, the first sealing member 2 includes an annular base 2a joined to a housing H, for example, of a compressor, a lip part 2b that defines an inner edge in contact with a rotational shaft S rotatably supported by the housing H, an annular containing part 2c and an incision 2d to which the core ring 1 is fitted in the base 2a. The second sealing member 3 includes a substantially flat outer edge part 3a, and a lip part 3b that defines an inner edge in contact with the rotational shaft S. The backup ring 4 includes a cylindrical part 4a that is fitted to the inside of the base 2a and a wall surface part 4b that defines a circular hole through which the rotational shaft S is passed.
In order to assemble these components, the incision 2d of the first sealing member 2 is greatly widened, and the core ring 1 is inserted into the containing part 2c. Thereafter, the second sealing member 3 is inserted into the inside of the first sealing member 2, and the backup ring 4 is incorporated by fitting the cylindrical part 4a to the inside of the base 2a in such a way as to sandwich the second sealing member 3 between the first sealing member 2 and the backup ring 4.
However, in the assemblage into the lip-type seal, there is a need to greatly widen the incision 2d while the base 2a is being deformed and maintain that state when the core ring 1 is inserted into the containing part 2c, and hence workability is remarkably inferior in assembling. On the other hand, a difficulty lies in detaching the core ring 1 when the core ring 1 is attempted to be detached therefrom after the lip-type seal is used for a long time, because the core ring 1 is completely buried in the containing part 2c so that there is no part to be gripped, and the core ring 1 is in a state of having been firmly embedded as a result of longtime use.
Additionally, in the assembled state of the lip-type seal, the second sealing member 3 is sandwiched between the first sealing member 2 and the backup ring 4. However, since the first sealing member 2 is made of rubber, there is a fear that the second sealing member 3 cannot be reliably sandwiched therebetween because of its elastic deformation or time-dependent change.
The present invention has been made in consideration of these circumstances of the prior art, and it is an object of the present invention to provide a lip-type seal in which components can be easily assembled while securing the sealing function inherent therein, in which the components can be easily disassembled and sorted out, and in which the components can be recycled.